Staff at a local Northland primary school are prepared to deal with life-threatening food allergy reactions in their students.
Preliminary results of a school-based survey reveal 8.5 per cent of students are allergic to one or more foods, with reactions ranging from itchy skin to life-threatening anaphylactic shock.
The findings came from the long-running CensusAtSchool survey project hosted by the Auckland University statistics department, with Statistics New Zealand and the Education Ministry.
Milk, eggs, peanuts and tree nuts were the most common food allergies identified.
Kokopu School administrator Vicki Lye said though none of the children currently at the school suffered severe food allergies, a draft policy was in place for any who did enrol.
"It asks children not to bring nuts and any food containing nuts to school."
Children with serious nut allergies had previously attended the school and all staff had been trained in the use of a EpiPen [epinephrine auto-injector] to prepare for a case of an anaphylactic shock.
The interim findings came from 2800 survey respondents aged 10 to 18. Up to 30,000 students from 539 schools are expected to take part by the survey's completion.
Paediatric allergy specialist Dr Allen Liang said the generally accepted figure for milk allergies was 3 to 5 per cent of the population, and 1 to 3 per cent were allergic to nuts.
Though children could grow out of milk and egg allergies, nut allergy sufferers were not so fortunate, he said.
Allergies usually occur within minutes of contact with food, and involve an exaggerated immune response causing symptoms including eczema, itchy skin, swelling, wheeze, vomiting and diarrhoea.
In the worst cases patients can suffer anaphylactic shock, a rare, life-threatening reaction that can involve constricted breathing and a collapse in blood pressure.
In some cases, simply touching the food is enough to provoke an allergic reaction.
A global trend showed all food allergies were increasing, with a rise in food additives a possible culprit, Dr Liang said.
The genetic ability to suffer an allergic reaction had always existed. However, greater exposure to a wider variety of foods had caused the prevalence of reactions, Dr Liang said.
Although deaths from nut allergies in New Zealand were uncommon, they had occurred.
Avoidance was the best remedy for allergy sufferers.